1. Field of the Invention
The present invention relates generally to photovoltaic mounting systems.
2. Description of the Related Art
After many years of experience installing Photovoltaic (PV) modules on commercial roof tops, it has become clear that there are economic advantages for a PV module mounting system to have a substructure that can adapt to different roof structural elements, such as beams and purlins, while being able to efficiently assemble as many PV modules onto a roof for maximum power production.
The roof mounting system should be viewed as having two distinct functions: 1) to adequately secure the optimal amount of PV modules (or groups of PV modules referred as panels) to effectively and economically orient the modules to produce power on the roof top; and 2) to adequately secure the PV modules or panels to the roof through a mechanism that is flexible enough to accommodate typical large flat roof structural elements.
Furthermore, there has been a greater understanding on environmental loads, particularly wind loads acting on large flat roof PV systems. By designing in the capability to move structural mounting components relative to the PV modules enables the PV system to remain secure, given the concentrations of forces that accumulate on certain regions of the PV array relative to the wind direction. During unseasonable wind events, such as a 300 year wind event, portions of the PV array will experience an uplifting acting force, and therefore it is necessary to have the PV racking components secured to each other. This notion of securing the entire rack to either a structural member or to other components of the array is often referred to as “load sharing” by those familiar with the art.